To overcome fading of wireless channels, an HARQ (Hybrid Automatic Repeat Request, hybrid automatic repeat request) mechanism is introduced at the physical layer of mobile communications. In the HARQ mechanism, if a receiver finds that a received data block is errored, the receiver requests a transmitter to retransmit the data block. Then, the receiver performs IR (Incremental Redundancy, incremental redundancy) processing on the data block retransmitted by the transmitter and the historically errored data block to improve the quality of receiving the data block.
IR processing in the HARQ mechanism means that the receiver must buffer errored data blocks historically received by the receiver in a place referred to as an IR buffer. In the prior art, the IR buffer is arranged in a SoC(System on Chip, system on chip) of the receiver, but the IR buffer , whose size is increased rapidly along with the increase of the air interface communication rate, which can reach 10 Mbit or above, may occupy over 20% of the SoC area, thereby increasing the cost of the SoC and cost of the receiver.